Sole pressure members

ABSTRACT

A unitary shoe pressure member has a surface for pressing a shoe conformed to a waist of a selected shoe style and size and a clearance for receiving a heel of the selected size shoe and another size shoe of the same, selected style and a method of making the unitary shoe pressure member by molding the member conformably to block halves each shaped conformably to a bottom member of the selected shoe.

Write l atent Chambers et al.

SOLE PRESSURE MEMBERS Inventors: Ferdinand Frank Chambers; Peter Hugh Vernon Dawson, both of Leicester, England Assignee: USM Corporation, Boston, Mass.

Filed: Sept. 10, 1973 Appl. No.: 396,124

US. Cl 12/146 R Int. Cl A43d Field of Search 12/142 R, 142 RS, 146 R,

References Cited UNITED STATES PATENTS 12/1940 Peterson 12/146 L Oct. 29, 1974 2,323,453 7/1943 Calderazzo 12/146 R 2,421,419 6/1947 Hardie 12/21 Primary Examiner-Patrick D. Lawson Attorney, Agent, or FirmRalph D. Gelling; Vincent A. White; Richard B. Megley [5 7] ABSTRACT 2 Claims, 5 Drawing Figures 1 SOLE PRESSURE MEMBERS BACKGROUND OF THE INVENTION This invention relates to shoe sole pressure members.

In the manufacture of shoes, it may be necessary to apply pressure over an outer surface of a shoe bottom member such as a shoe sole. For example, such pressure is desirable when a shoe bottom member is to be attached to an upper by an adhesive. Bottom member attaching pressure is then commonly applied by a machine which comprises a pad box arranged to provide substantially uniformly distributed pressure over at least a bottom surface of the bottom member by urging the pad box toward an upper support of the machine so as to press the shoe bottom member against a lasted shoe upper disposed between the support and pad-boxsupported bottom member. Commonly, the pad box comprises a plurality of pieces of resilient material arranged to provide a composite pressure applying surface which operates on the bottom surface of the shoe bottom member to which pressure is to be applied. It is convenient to so construct the pad box with a plurality of pieces of material in order to readily adapt the pad box for applying pressure to different configurations of shoe bottom members. However, difficulty has been experienced in adapting such pad boxes for applying suitable pressure to shoe bottom members of some configurations, for example, those which involve a deep waist portion and a high, chunky heel.

SUMMARY OF THE INVENTION Accordingly, it is one of the objects of the present invention to provide a sole pressure member.

It is another of the various objects of the present invention to provide a method of making a sole pressure member.

To these ends, the invention provides a pressure member for use in a machine for applying distributed pressure to a bottom surface of a shoe bottom member, the pressure member being a unitary or single piece of material and having a bottom member contacting surface configured to conform to the bottom surface of the bottom member. The pressure member may be made from any suitable, somewhat elastomeric material of solid or foamed composition. The pressure member material should be sufficiently rigid to apply necessary pressures to the bottom member, but a certain degree of resilience in the material may often be desirable. Preferably, the surface of the pressure member is shaped to conform not only to the bottom surface of the selected shoe bottom member, but also to the bottom surfaces of shoe bottom members of the same style or configuration but of different sizes, the pad thus being suitable for usein attaching a range of sizes of shoe bottom members of the same style.

A method of making the pressure chamber comprises procuring a molding frame which defines a cavity and a block cooperative with the frame so that an outer surface of the block corresponds to an inner surface of the frame, shaping a surface of the block substantially into conformity with a bottom surface of a selected shoe bottom member, placing the block in the molding frame so that the surface of the block shaped substantially into conformity with the shoe bottom member and portions of the molding frame together define a mold, casting pressure member material in the mold, and curing and removing the pressure member material from the mold as a pressure member.

Preferably, the molding frame has an open top and steadily decreasing cross-sectional area between the top and a bottom defined by an endless wall to aid removal of the pressure member from the frame. Preferably, too, the block may be severed into parts to facilitate shaping of the block. In a preferred practice of the method, the block is divided into two parts along a center line of the block so that the surface of the block is to be shaped to conform with the bottom surface of the selected shoe bottom member is divided equally between the two parts. Each of the two parts of the block is then shaped with the aid of a thin template having an edge which corresponds in profile to the profile of a center line of the bottom surface of the selected shoe bottom member. After shaping of each of the two parts of the block, the two parts are adhesively reunited with the template between them to make up for the material removed when the block was severed into the two parts. The reunited block is then placed in the molding frame. The surface of the block may also be sealed to obviate production of unwanted flash when the pressure member is molded on the block. A sealing material may also conveniently serve as a mold release.

DESCRIPTION OF THE DRAWINGS FIG. 2 is a side elevation of the preferred pressure member for applying pressure to the bottom member shown in FIG. 1;

FIG. 3 is a top view of a mold for making the pressure member;

FIG. 4 is a perspective view of a portion of the mold shown in FIG. 3; and

FIG. 5 is a sectional view of the mold shown in FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 shows a shoe having a bottom member generally at 2 known as a sole and heel unit. The bottom member has a high waist portion 4 and a chunky heel 6 and, accordingly, is difficult to adhesively attach to an upper 8 with conventional multi-piece members in a pad box (not shown) of a known machine (not shown) for pressing shoe bottom members against shoe uppers.

FIG. 2 shows a preferred pressure member 10 for pressing the bottom member illustrated at 2 onto the upper 8. For this purpose the pressure member 10 is mounted in the pad box of the known machine for engaging a bottom surface 12 (FIG. 1) of the bottom member with an upper surface 14 of the pressure member 10. The pressure member then uniformly presses the bottom member against the upper.

A sole attaching operation may then be performed as follows: the illustrated pressure member 10 is mounted in a pad box on a sole attaching machine (not shown) and the upper 8, with the sole and heel unit 2 spotted thereon, is positioned on the member with the heel of the unit 2 received in a clearance at 16 in the member. At this stage in the manufacture of a shoe, the sole and heel unit 2 has a coating of adhesive on an attaching surface for bonding to the lasted upper 8 of the shoe, which upper may also have a coating of adhesive. The sole attaching machine is operated to raise the pad box until the upper 8 comes into engagement with supports of the machine. Sole attaching pressure is then applied by the machine to the shoe bottom between the pad box and the supports. The illustrative member 10, being somewhat yieldable and shaped as hereinafter described to conform to widthwise as well as lengthwise contours of a bottom surface of the sole and heel unit, exerts distributed pressure over the bottom surface to effect adequate bonding of the sole and heel unit to the lasted upper of the shoe.

The member 10 is manufactured by a preferred method now to be described. In the method, the member 10 is cast in a mold at 20 in FIGS. 3 and 5. The mold comprises a frame 22, preferably of an epoxy resin material, enclosing two shaped inserts 24 forming a block preferably of foamed, rigid, polyurethane material. The frame 22 provides an endless wall which defines a cavity open at both ends, the internal face 26 of the wall of the frame tapering outwardly from a bottom portion 28 of the face of the frame to an opposite top face thereof to give a larger cavity opening at the top of the frame than at the bottom.

The inserts 24 are made of foamed, rigid, polyurethane because blocks of the material can readily be cast in the frame itself to closely fit its cavity and the material is easily worked to give the surface 14 a shape corresponding to the shoe bottom surface 12. A material having a density of about 0.3 grms/c.c. has been found to be suitable for the purpose.

A bottom (not shown) may be placed under the wall defined cavity adjacent the face 28 and a two-part mix suitable for producing the inserts 24 poured into the cavity 18. Equal parts of commercially available polyol plus blowing agent and isocyanate have been used. After mixing for 30 seconds, it was poured into the cavity, the frame 14 then receiving a top cover (not shown) opposite the bottom. Expansion of the material commenced after 90 seconds and it took about 10 minutes to produce a block for the inserts of foamed, rigid polyurethane which was then removed from the cavity in the frame by pushing from the smaller end of the cavity. Enough foam forming material is poured into the cavity to form a rigid block which completely fills the cavity. A supply of blocks of foamed rigid polyurethane can be made in this way ready for use in producing shaped inserts 24 according to the shape of the bottom members to be attached.

To produce the member 10, the lengthwise profile shape of a made up, selected shoe or the sole and heel unit at 2 if it is rigid enough normally to adopt the correct profile shape before being attached to a lasted upper is selected and set on an adjustable profile gauge (not shown). The profile is taken with the gauge on a line of the crest of the widthwise curvature in the waist of the shoe and continued along the crest of the widthwise curvature in the forepart. If the shoe has a fairly straight heel to toe center line and uniform widthwise curvature each side of the centerline, the same pad may be suitable for use on both rights and lefts but in other cases it may be necessary to provide separate pressure members for right and left bottom members.

A block previously cast in the frame 20 and from which the inserts 24 are to be formed is sawed into halves along its lengthwise center line to give a flat surface 30 on each half on which to mark the profile shape set on the profile gauge. The profile shape is marked on a piece of card using the set profile gauge as a guide and the marked shape cut out; the cut card 32 is then used as a template to mark the shape on each flat surface 30.

Each insert 24 is shaped laterally by cutting and filing to correspond to the widthwise curvature of the bottom of the waist 4 of the unit, the waist curvature being continued to the outer edge of each insert 24. The curvature of a break line 34 on each insert 16 is obtained with a compass and marked it on the appropriate insert 24. The insert is then filed to this line to blend in the waist with the forepart.

The cut-out card template 32 is then adhesively attached between the shaped inserts 24 to make up the saw-cut-out material and the inserts with card between pressed into the cavity of the frame 22.

The cavity then defined by the shaped top of the inserts 24 and, together with the portion of the internal face 26 of the frame projecting above the inserts, provides the mold shape in which the member 10 is cast. The mold is coated with a suitable substance to prevent leaking past joints in the mold and to prevent absorption into the inserts 24. Plasticine mixed with linseed oil has been found to be suitable for this purpose.

To form the member 10, a two-part mix of polyol and isocyanate is mixed for 30 seconds and poured into the mold. The chemical reaction gives a set member in a time dependent on the total weight of material in the member. Sufficient material is poured into the mold to fill it flush with the top of the frame 22. A smooth flat surface is achieved by placing a flat weighted cover (not shown) over the cavity and resting the mold on the cover while the reaction takes place. The member 10 is then removed from the mold by pushing the inserts 24 from the bottom to urge it and thus the member 10 from the frame. The member 10 is then ready for use as hereinbefore described.

The member 10 is preferably adapted for use on a range of sizes of sole and heel units of the same style. The break line 34 is the datum line from which each size is measured. Thus, when marking out the template card 32 the position of the breakline lengthwise of the card is first determined. The longest size toeward and heelward of the break line is accomodated within the length of the card and then the waist and forepart shapes obtained by use of the profile gauge on the smallest size in the range marked on the card. The waist and forepart curves are continued beyond the end positions of the smallest size in order to accommodate the larger sizes, and the back of the heel position of the largest size is also marked on the card. Thus, the inserts 24 have the clearance 16 to receive the heel of the largest sole and heel unit to be attached. The heel of a larger size shoe may be higher than the heel of a smaller shoe but its tread face will lie in the same plane relative to the tread surface of the forepart as for the smaller; thus, the sole and heel unit of both sizes will sit correctly on surface 14 obtained from the profile of the smaller size.

the shaped block halves in the mold cavity; and molding the pressure member conformably to the shaped block halves in the mold cavity.

2. A method as in claim 1 wherein the template is assembled between the block halves prior to placing the block halves in the mold cavity for compensating for block material removed when separating the block into halves. 

1. A method of making a unitary shoe pressure member, comprising the steps of: procuring a molding frame defining a cavity and a block having an outer surface corresponding to the cavity; separating the block into longitudinal halves; shaping a card into a template conformable to a selected shoe bottom member; shaping each block half conformably to the template; placing the shaped block halves in the mold cavity; and molding the pressure member conformably to the shaped block halves in the mold cavity.
 2. A method as in claim 1 wherein the template is assembled between the block halves prior to placing the block halves in the mold cavity for compensating for block material removed when separating the block into halves. 